Análise comparativa de vibração em motores ciclo diesel com combustível comercial e biodiesel

Abstract

The main objective of this study is to analyze the vibrations arising from an internal combustion cycle diesel engine using two different fuels, commercial diesel (B8) and Biodiesel (B100). In addition, the consumption, the level of particulate emitted in the atmosphere and the temperature of the engine were analyzed as complementary data. Experiments were performed with the motor non-invasively installed in the vehicle. From the experimental results, it was possible to verify the energetic loss of the engine, taking into account the two types of tested fuels (B8 and B100) from the collected vibration signals. The tests were carried out taking into account three distinct rotations: 800 rpm, which corresponds to idle, 1800 rpm that corresponds to the rotation relative to the maximum torque of the engine and 3600 rpm, which corresponds to the rotation of higher engine power. The data collected allowed a quantitative assessment of how each fuel influences the vibration level of the engine. In the three analyzed rotations, diesel B8 showed to be more energetic in relation to the vibration level when compared to B100 and the temperature remained constant. Although the consumption using biodiesel B100 presented values slightly higher, the level of particulate emitted to the atmosphere was inferior. It was also noted that the vibration increased in both cases, as the engine speed increased, being the diesel B8 presented a total vibration index with rotations ranging from 4.5 to 21%, presenting values higher than B100. Therefore, the dissipated vibration energy was higher using the B8 diesel, which was 10 to 45% higher than the B100, taking into account engine rotation. With this, it is concluded that combustion generates higher level of vibration in internal combustion engines, depending on the kind of used fuel.